This invention relates to remote meter reading in general and more particularly to an improved remote meter reader which provides an accurate reading output at the meter. In U.S. Pat. No. 4,007,454, granted to Charles Cain there is disclosed a remote meter reading system which utilizes a rotating electric field concentric with the center of rotation of the meter needle. The interaction of the meter needle with this field is utilized to obtain an indication of needle position by comparing the phase of the detected signal with that of a reference signal.
In a meter reading device of this nature a problem may arise because of mechanical inaccuracies in the meter. As will be well recognized, most meters which must be read constitute a plurality of dials (or hands) which represent, for example, kilowatt hours, tens of kilowatt hours, hundreds of kilowatt hours and thousands of kilowatt hours. In some cases the hands are not accurately aligned. For example, if the reading of the kilowatt hand is at two, having just passed zero, the tens of kilowatt dial should be 2/10's of the digital distance beyond a significant digit, say 0.2. Due to misalignment, however, the tens of kilowatt dial may, for example, be at 9.9. If the dial readings are obtained independently, errors can clearly be carried through the system. Another approach is: data from each dial is obtained with more resolution and decoded at a central location--more data must be transmitted.